Merge pull request #634 from iNavFlight/improved_fw_iterm_limiting

Improvements for FixedWing Iterm limiting

docs/Cli.md

@@ -255,7 +255,7 @@ Re-apply any new defaults as desired.
 | `nav_max_climb_rate`           | Maximum climb/descent rate that UAV is allowed to reach during navigation modes. In cm/s                                                                                                                             | 10      | 2000     | 500             | Master       | UINT16    |  
 | `flaperon_throw_offset`           | Defines throw range in us for both ailerons that will be applied (before scaling) when FLAPERON mode is activated. | 100      | 400     | 250             | Profile       | UINT16    |  
 | `flaperon_throw_inverted`           | Inverts throw offset on both ailerons. Can be used to create SPOILERON or just to change throw direction | OFF      | ON     | OFF             | Profile       | UINT8    |  
-| `fw_iterm_throw_limit`           | Limits max/min I-term value in stabilization PID controller in case of Fixed Wing. It solves the problem of servo saturation before take-off/throwing the airplane into the air. By default, error accumulated in I-term can not exceed 1/3 of servo throw (around 165us).   | 25      | 500     | 165             | Profile       | UINT16    |  
+| `fw_iterm_throw_limit`           | Limits max/min I-term value in stabilization PID controller in case of Fixed Wing. It solves the problem of servo saturation before take-off/throwing the airplane into the air. By default, error accumulated in I-term can not exceed 1/3 of servo throw (around 165us). Set `0` to disable completely.  | 0      | 500     | 165             | Profile       | UINT16    |  
 
 ## New iNav specific
 | `Variable`                                    | Description/Units                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        | Min    | Max    | Default          | Type         | Datatype |

src/main/flight/pid.c

@@ -334,7 +334,7 @@ static void pidApplyRateController(const pidProfile_t *pidProfile, pidState_t *p
     }
 
 #ifdef USE_SERVOS
-    if (STATE(FIXED_WING)) {
+    if (STATE(FIXED_WING) && pidProfile->fixedWingItermThrowLimit != 0) {
         pidState->errorGyroIf = constrainf(pidState->errorGyroIf, -pidProfile->fixedWingItermThrowLimit, pidProfile->fixedWingItermThrowLimit);
     }
 #endif

src/main/flight/pid.h

@@ -28,7 +28,7 @@
 #define MAG_HOLD_RATE_LIMIT_DEFAULT 90
 
 #define FW_ITERM_THROW_LIMIT_DEFAULT 165
-#define FW_ITERM_THROW_LIMIT_MIN 25
+#define FW_ITERM_THROW_LIMIT_MIN 0
 #define FW_ITERM_THROW_LIMIT_MAX 500
 
 #define AXIS_ACCEL_MIN_LIMIT    50